1. Field of the Invention
The present invention relates to a system for determining authenticity of software in an information processing apparatus. More specifically, the present invention relates to a system for determining whether software contained in an external memory, for example, ROM cartridge, floppy disk or the like, is authorized for use with a main processor unit.
2. Description of the Prior Art
Conventionally, such information processing apparatus are known wherein an external memory is loaded in a main processor unit and the main unit executes a predetermined program according to software contained in this external memory. One example of such a data processing apparatus is the "Nintendo Entertainment System (trade mark)" manufactured and sold by the assignee of the present application. The "Nintendo Entertainment System" which embodies the present invention includes a ROM cartridge, which is shown in the Nintendo publication distributed in the Fall of 1985 entitled "We're Changing the Face of Home Entertainment", copyright 1985. The identical ROM cartridge also is shown in U.S. design patent Des. 294, 020, filed Oct. 7, 1985. This ROM cartridge (external memory) is loaded into a front loading main processor unit (as is also shown in the 1985 Nintendo publication), the main processor unit is connected to a television receiver, and thereby various games can be enjoyed on the screen of the television receiver. A large number of software programs (ROM cartridges) are available for use in such, information processing apparatus. However, such authentic software programs are subject to being imitated and counterfeited and it is desirable to provide a system that enables data processing of only authentic program cartridges.